Forgetfulness of continuous Markovian quantum channels

The notion of forgetfulness, used in discrete quantum memory channels, is slightly weakened in order to be applied to the case of continuous channels. This is done in the context of quantum memory channels with Markovian noise. As a case study, we apply the notion of weak-forgetfulness to a bosonic memory channel with additive noise. A suitable encoding and decoding unitary transformation allows us to unravel the effects of the memory, hence the channel capacities can be computed using known results from the memoryless setting.Comment: 6 pages, 2 figures, comments are welcome. Minor corrections and acknoledgment adde

Stationary states of open XX-spin chains

We study an open quantum spin chain of arbitrary length with nearest neighbor X X interactions of strength g, immersed in an external constant magnetic field Δ along the z direction, whose end spins are weakly coupled to two heat baths at different temperatures. In the so-called global approach, namely, without neglecting interspin interactions, using standard weak-coupling limit techniques, we first derive the open chain master equation written in terms of fermionic mode operators. Then, we focus on the study of the dependence of the resulting open dynamics from the ratio r ≡ g/Δ. By increasing r, some of the chain Bohr transition frequencies become negative; when this occurs, both the generator of the dissipative time evolution and its stationary states behave discontinuously. As a consequence, the asymptotic spin and heat flows also exhibit discontinuities, but in a different way: while source terms in the spin flow continuity equation show jumps, the heat flow instead is continuous but with discontinuous first derivatives with respect to r. These two behaviors might be experimentally accessible; in particular, they could discriminate between the global and the local approaches to open quantum spin chains. Indeed, the latter one, which neglects interspin interactions in the derivation of the master equation, does not show any kind of discontinuous behavior

Single unconfined compression of cellular dense collagen scaffolds for cartilage and bone tissue engineering

Cell seeded collagen matrix scaffolds have been extensively evaluated recently as potential systems for de-novo tissue regeneration and repair for a variety of tissue types. While collagen gels are biologically excellent as starting point scaffold materials, their use is limited by the lack of cohesive structure and inherently weak mechanical properties due to a high liquid content (>99%). An ingenious method of combining unconfined plastic compression (PC) with capillary action has shown that these scaffolds can be rapidly processed into tissue like structures, which can be immediately implanted into the host[1]. It has been shown that the rapid increase in fibrillar collagen density dramatically enhanced the mechanical properties of such scaffolds thus potentially eliminating the need for long term cellular action. This simple project investigated the effect of single unconfined compression on cartilage-cell seeded collagen matrices in terms of cell viability, proliferation and oxygen consumption

The matrix product representations for all valence bond states

We introduce a simple representation for irreducible spherical tensor operators of the rotation group of arbitrary integer or half integer rank and use these tensor operators to construct matrix product states corresponding to all the variety of valence-bond states proposed in the Affleck-Kennedy-Lieb-Tasaki (AKLT) construction. These include the fully dimerized states of arbitrary spins, with uniform or alternating patterns of spins, which are ground states of Hamiltonians with nearest and next-nearest neighbor interactions, and the partially dimerized or AKLT/VBS (Valence Bond Solid) states, which are constructed from them by projection. The latter states are translation-invariant ground states of Hamiltonians with nearest-neighbor interactions.Comment: 24 pages, references added, the version which appears in the journa

Antibacterial effect of copper-bearing titanium alloy (Ti-Cu) against Streptococcus mutans and Porphyromonas gingivalis

This work was financially supported by the National Natural Science Foundation (No. 81301329, No. 81271957 and No. 81530051), Joint foundation of Liaoning Province Natural Science Foundation and Shenyang National Laboratory for materials science (No. 2015021004), Youth Innovation Promotion Association, CAS (No. 2014168), and The Dunhill Medical Trust (R360/0514)

A single-center non-blinded randomized clinical trial to assess the safety and effectiveness of PhR160 spray in the treatment of COVID-19 pneumonia

7-16COVID-19 is an emerging pandemic that caused a very widespread infection with more than 1000000 cases in Iran within a year. The main cause of mortality among patients with COVID-19 is pulmonary failure. In Iranian Traditional Medicine, essences have been used for curing pulmonary diseases. Pinen-Hydronoplacton-Ribonucleic acid (PHR) is an inhaler spray made of seven different plants, which all are used by humans and have desirable pharmacological features for treating pulmonary symptoms of COVID-19 patients. This study was conducted to assess the safety and effectiveness of PHR160 spray in improving pulmonary symptoms of COVID-19 patients. This was a single-centre, non-blinded randomized clinical trial with two parallel groups in two different wards of Baqiyatallah hospital, Tehran, Iran. Participants were 63 male patients diagnosed with COVID-19 pneumonia, divided into 2 groups of 32 in the intervention group and 31 in the control group. The intervention group received 5 days of PHR160 spray, 10 puffs each day, 300 micrograms in each puff in addition to the routine treatment. Oxygen saturation was measured by a pulse oximeter, every six hours and recorded daily. This study showed that administration of PhR 160 in patients of COVID-19 was safe, and it significantly increased the arterial oxygen saturation percentage in COVID-19 patients. In addition, it decreased hospitalization duration, dyspnea score, and cough score significantly in the patients. The statistical modelling test, with adjusting the age and respiratory rate for baseline and 4 days of the intervention, shows that the oxygen saturation percentage mean was significantly more in the intervention group by 5.14 units (p<0.001)

The Pace of Prostatic Intraepithelial Neoplasia Development Is Determined by the Timing of Pten Tumor Suppressor Gene Excision

Loss of the PTEN tumor suppressor is a common occurrence in human prostate cancer, particularly in advanced disease. In keeping with its role as a pivotal upstream regulator of the phosphatidylinositol 3-kinase signaling pathway, experimentally-induced deletion of Pten in the murine prostate invariably results in neoplasia. However, and unlike humans where prostate tumorigenesis likely evolves over decades, disease progression in the constitutively Pten deficient mouse prostate is relatively rapid, culminating in invasive cancer within several weeks post-puberty. Given that the prostate undergoes rapid androgen-dependent growth at puberty, and that Pten excisions during this time might be especially tumorigenic, we hypothesized that delaying prostate-specific Pten deletions until immediately after puberty might alter the pace of tumorigenesis. To this end we generated mice with a tamoxifen-inducible Cre recombinase transgene enabling temporal control over prostate-specific gene alterations. This line was then interbred with mice carrying floxed Pten alleles. Despite evidence of increased Akt/mTOR/S6K axis activity at early time points in Pten-deficient epithelial cells, excisions induced in the post-pubertal (6 wk-old) prostate yielded gradual acquisition of a range of lesions. These progressed from pre-malignant changes (nuclear atypia, focal hyperplasia) and low grade prostatic intraepithelial neoplasia (PIN) at 16–20 wks post-tamoxifen exposure, to overtly malignant lesions by ∼1 yr of age, characterized by high-grade PIN and microinvasive carcinoma. In contrast, when Pten excisions were triggered in the pre-pubertal (2 week-old) prostate, neoplasia evolved over a more abbreviated time-frame, with a spectrum of premalignant lesions, as well as overt PIN and microinvasive carcinoma by 10–12 wks post-tamoxifen exposure. These results indicate that the developmental stage at which Pten deletions are induced dictates the pace of PIN development

Wavelet-based identification of DNA focal genomic aberrations from single nucleotide polymorphism arrays

<p>Abstract</p> <p>Background</p> <p>Copy number aberrations (CNAs) are an important molecular signature in cancer initiation, development, and progression. However, these aberrations span a wide range of chromosomes, making it hard to distinguish cancer related genes from other genes that are not closely related to cancer but are located in broadly aberrant regions. With the current availability of high-resolution data sets such as single nucleotide polymorphism (SNP) microarrays, it has become an important issue to develop a computational method to detect driving genes related to cancer development located in the focal regions of CNAs.</p> <p>Results</p> <p>In this study, we introduce a novel method referred to as the wavelet-based identification of focal genomic aberrations (WIFA). The use of the wavelet analysis, because it is a multi-resolution approach, makes it possible to effectively identify focal genomic aberrations in broadly aberrant regions. The proposed method integrates multiple cancer samples so that it enables the detection of the consistent aberrations across multiple samples. We then apply this method to glioblastoma multiforme and lung cancer data sets from the SNP microarray platform. Through this process, we confirm the ability to detect previously known cancer related genes from both cancer types with high accuracy. Also, the application of this approach to a lung cancer data set identifies focal amplification regions that contain known oncogenes, though these regions are not reported using a recent CNAs detecting algorithm GISTIC: SMAD7 (chr18q21.1) and FGF10 (chr5p12).</p> <p>Conclusions</p> <p>Our results suggest that WIFA can be used to reveal cancer related genes in various cancer data sets.</p

“Topological Significance” Analysis of Gene Expression and Proteomic Profiles from Prostate Cancer Cells Reveals Key Mechanisms of Androgen Response

The problem of prostate cancer progression to androgen independence has been extensively studied. Several studies systematically analyzed gene expression profiles in the context of biological networks and pathways, uncovering novel aspects of prostate cancer. Despite significant research efforts, the mechanisms underlying tumor progression are poorly understood. We applied a novel approach to reconstruct system-wide molecular events following stimulation of LNCaP prostate cancer cells with synthetic androgen and to identify potential mechanisms of androgen-independent progression of prostate cancer.We have performed concurrent measurements of gene expression and protein levels following the treatment using microarrays and iTRAQ proteomics. Sets of up-regulated genes and proteins were analyzed using our novel concept of "topological significance". This method combines high-throughput molecular data with the global network of protein interactions to identify nodes which occupy significant network positions with respect to differentially expressed genes or proteins. Our analysis identified the network of growth factor regulation of cell cycle as the main response module for androgen treatment in LNCap cells. We show that the majority of signaling nodes in this network occupy significant positions with respect to the observed gene expression and proteomic profiles elicited by androgen stimulus. Our results further indicate that growth factor signaling probably represents a "second phase" response, not directly dependent on the initial androgen stimulus.We conclude that in prostate cancer cells the proliferative signals are likely to be transmitted from multiple growth factor receptors by a multitude of signaling pathways converging on several key regulators of cell proliferation such as c-Myc, Cyclin D and CREB1. Moreover, these pathways are not isolated but constitute an interconnected network module containing many alternative routes from inputs to outputs. If the whole network is involved, a precisely formulated combination therapy may be required to fight the tumor growth effectively